Tunnel beam



FIG. 1 is a bottom view of the tunnel beam showing my new design

FIG. 2 is a left side view thereof

FIG. 3 is a front view thereof

FIG. 4 is a right side view thereof

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a side elevational view thereof.

The broken lines shown are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a tunnel beam, as shown and described. 